It is known to wind cables or wires into coils for further storing, shipping or further processing. It is known to make coils by winding the cable or wire into a drum-like cavity of a non-rotating winding apparatus, as disclosed e.g. by DE 42 35 007; this method is not suitable for preparing coils with ends ready for further processing, also because it is not possible to control the radius of curvature of the cable. The radius of curvature can be controlled by using a coil forming apparatus where the cable is wound around a coil former; once the coil has been formed around the forming nucleus, the former's diameter is decreased to allow safe removal of the coil.
In fact, one problem faced by the known methods and apparatuses is to provide a required length for the two cable ends for further processing of the cable at its two ends. U.S. Pat. No. 6,948,675 discloses an apparatus for making coils from a length of cable (namely fiber optic cable); the apparatus has a coil former and two grippers for the two ends of the cable, the grippers are movable by means of relevant carriages on rails, so as to adjust the lengths of the two ends to be the same or almost the same. In this embodiment, the two grippers hold the two ends of the cable and are aligned to each other during the final step of adjusting the length of the free ends.
WO2010/001342 discloses an apparatus for coiling pieces of cable or of wire. The cable is first cut into the desired length and then wound around a coil former; the coil former has a diameter that can be modified and controlled. According to WO'342, the diameter of the coil former is changed during the winding of the cable in order to have a final free end (trailing end) of the coil having the required length, substantially identical to the first free end (leading end) of the coil.
Actually, changing the diameter of the coil during the forming of the coil is a step very difficult to achieve, especially once a couple of windings have been provided on the coil former. Another problem of this document is that the cable (or wire) has to be cut into the desired length in advance; a cut cable may be difficult to handle, especially if the cable is longer than a few meters, e.g. longer than 3-4 meters.
It is an aim of the present invention to solve the above problems and to provide an apparatus and a process in which a continuous cable is fed to the coil-forming machine, is coiled and can be cut into the desired length with great accuracy, and wherein the two cable's ends protrude from the same side of the coil and have a predetermined length, and preferably the same length.